Difference between std::string::resize and std::string::erase when shortening string

Question

When shortening a std::string there are basically two possibilities: string.resize(length) or string.erase(length).

Given that we know a string will become smaller, what are the differences between the two?

Answer 1

1. resize must check if length > current or length < current - it's behavior depends on result of сomparison. erase always reduce length of string
2. There is difference in exception safety:
   • resize: Strong guarantee: if an exception is thrown, there are no changes in the string. ( from here )
   • erase: C++98 - equal to resize; C++14 - there is no-throw version of function ( from here )